1. Field of the Invention
This invention relates to buttons for actuating switches.
2. Description of the Related Art
Many computer systems, including personal computers, workstations, servers, and embedded systems are designed to have multiple peripheral devices included in the system. A typical personal computer system includes a processor, associated memory and control logic and a number of peripheral devices that provide input and output (I/O) for the system. Such peripheral devices include, for example, compact disk read-only memory (CD-ROM) drives, hard disk drives, floppy disk drives, and other mass storage devices such as tape drives, compact disk recordable (CD-R) drives or digital video/versatile disk (DVD) drives. Additionally, computer systems often have the capability to interface with external enclosures that include additional peripheral devices.
The computer systems, their included peripheral devices, associated external enclosures, and many other electronic devices typically have one or more external buttons providing user control of one or more functions of the device, e.g a power button. Often, the button is not itself a switch, but rather an actuator that when pushed activates a switch internal to the device, e.g. a momentary on/off switch attached to the power circuit of a computer system. A common design for such button assemblies is shown in the cross-sectional drawings of FIGS. 1A and 1B. Button 100 includes tabs 102 and center post 104. Compression spring 120 has an inner diameter large enough to accommodate center post 104. Once inserted into button housing 130, tabs 102 of button 100 engage the rear portions 132 of the button housing. Button housing 130 is typically formed as part of a chassis, enclosure, or front bezel for a computer system or other device. Center post 104 is free to move within hole 136, and spring 120 is compressed between button 100 and spring supports 134. When installed, button 100, spring 120, and button housing 130 combine to form button assembly 140 as illustrated in FIG. 1B. When pushed in the direction of arrow 150, spring 120 compresses, and button 100 can actuate a switch (not shown) with center post 104, or some other actuating portion. When button 100 is released, spring 120 forces the button in a direction opposite to that of arrow 150, until the buttons motion is constrained by tabs 102 engaging button housing rear portions 132.
The button assembly of FIGS. 1A and 1B requires at least two parts, button 100 and spring 120. Increasing the number of parts both increases the cost of the button assembly, and complicates construction of button assembly 140. Additionally, the prior art design including spring 120 uses a complicated button housing molded into the bezel or enclosure. Accordingly, it is desirable to have a single piece button that can easily be installed into a simplified bezel or enclosure.